/**
 * @author 张慧华 z@j-ui.com
 * ----------------------------------------------------------
 * These functions use the same 'format' strings as the
 * java.text.SimpleDateFormat class, with minor exceptions.
 * The format string consists of the following abbreviations:
 *
 * Field        | Full Form          | Short Form
 * -------------+--------------------+-----------------------
 * Year         | yyyy (4 digits)    | yy (2 digits), y (2 or 4 digits)
 * Month        | MMM (name or abbr.)| MM (2 digits), M (1 or 2 digits)
 *              | NNN (abbr.)        |
 * Day of Month | dd (2 digits)      | d (1 or 2 digits)
 * Day of Week  | EE (name)          | E (abbr)
 * Hour (1-12)  | hh (2 digits)      | h (1 or 2 digits)
 * Hour (0-23)  | HH (2 digits)      | H (1 or 2 digits)
 * Hour (0-11)  | KK (2 digits)      | K (1 or 2 digits)
 * Hour (1-24)  | kk (2 digits)      | k (1 or 2 digits)
 * Minute       | mm (2 digits)      | m (1 or 2 digits)
 * Second       | ss (2 digits)      | s (1 or 2 digits)
 * AM/PM        | a                  |
 *
 * NOTE THE DIFFERENCE BETWEEN MM and mm! Month=MM, not mm!
 * Examples:
 *  "MMM d, y" matches: January 01, 2000
 *                      Dec 1, 1900
 *                      Nov 20, 00
 *  "M/d/yy"   matches: 01/20/00
 *                      9/2/00
 *  "MMM dd, yyyy hh:mm:ssa" matches: "January 01, 2000 12:30:45AM"
 * ----------------------------------------------------------
 */
(function () {
    var MONTH_NAMES = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
    var DAY_NAMES = new Array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');

    function LZ(x) {
        return (x < 0 || x > 9 ? "" : "0") + x
    }

    /**
     * formatDate (date_object, format)
     * Returns a date in the output format specified.
     * The format string uses the same abbreviations as in parseDate()
     * @param {Object} date
     * @param {Object} format
     */
    function formatDate(date, format) {
        format = format + "";
        var result = "";
        var i_format = 0;
        var c = "";
        var token = "";
        var y = date.getYear() + "";
        var M = date.getMonth() + 1;
        var d = date.getDate();
        var E = date.getDay();
        var H = date.getHours();
        var m = date.getMinutes();
        var s = date.getSeconds();
        var yyyy, yy, MMM, MM, dd, hh, h, mm, ss, ampm, HH, H, KK, K, kk, k;
        // Convert real date parts into formatted versions
        var value = {};
        if (y.length < 4) {
            y = "" + (y - 0 + 1900);
        }
        value["y"] = "" + y;
        value["yyyy"] = y;
        value["yy"] = y.substring(2, 4);
        value["M"] = M;
        value["MM"] = LZ(M);
        value["MMM"] = MONTH_NAMES[M - 1];
        value["NNN"] = MONTH_NAMES[M + 11];
        value["d"] = d;
        value["dd"] = LZ(d);
        value["E"] = DAY_NAMES[E + 7];
        value["EE"] = DAY_NAMES[E];
        value["H"] = H;
        value["HH"] = LZ(H);
        if (H == 0) {
            value["h"] = 12;
        } else if (H > 12) {
            value["h"] = H - 12;
        } else {
            value["h"] = H;
        }
        value["hh"] = LZ(value["h"]);
        if (H > 11) {
            value["K"] = H - 12;
        } else {
            value["K"] = H;
        }
        value["k"] = H + 1;
        value["KK"] = LZ(value["K"]);
        value["kk"] = LZ(value["k"]);
        if (H > 11) {
            value["a"] = "PM";
        } else {
            value["a"] = "AM";
        }
        value["m"] = m;
        value["mm"] = LZ(m);
        value["s"] = s;
        value["ss"] = LZ(s);
        while (i_format < format.length) {
            c = format.charAt(i_format);
            token = "";
            while ((format.charAt(i_format) == c) && (i_format < format.length)) {
                token += format.charAt(i_format++);
            }
            if (value[token] != null) {
                result += value[token];
            } else {
                result += token;
            }
        }
        return result;
    }

    function _isInteger(val) {
        return (new RegExp(/^\d+$/).test(val));
    }

    function _getInt(str, i, minlength, maxlength) {
        for (var x = maxlength; x >= minlength; x--) {
            var token = str.substring(i, i + x);
            if (token.length < minlength) {
                return null;
            }
            if (_isInteger(token)) {
                return token;
            }
        }
        return null;
    }

    /**
     * parseDate( date_string , format_string )
     *
     * This function takes a date string and a format string. It matches
     * If the date string matches the format string, it returns the date.
     * If it does not match, it returns 0.
     * @param {Object} val
     * @param {Object} format
     */
    function parseDate(val, format) {
        val = val + "";
        format = format + "";
        var i_val = 0;
        var i_format = 0;
        var c = "";
        var token = "";
        var token2 = "";
        var x, y;
        var now = new Date(1900, 0, 1);
        var year = now.getYear();
        var month = now.getMonth() + 1;
        var date = 1;
        var hh = now.getHours();
        var mm = now.getMinutes();
        var ss = now.getSeconds();
        var ampm = "";

        while (i_format < format.length) {
            // Get next token from format string
            c = format.charAt(i_format);
            token = "";
            while ((format.charAt(i_format) == c) && (i_format < format.length)) {
                token += format.charAt(i_format++);
            }
            // Extract contents of value based on format token
            if (token == "yyyy" || token == "yy" || token == "y") {
                if (token == "yyyy") {
                    x = 4;
                    y = 4;
                }
                if (token == "yy") {
                    x = 2;
                    y = 2;
                }
                if (token == "y") {
                    x = 2;
                    y = 4;
                }
                year = _getInt(val, i_val, x, y);
                if (year == null) {
                    return 0;
                }
                i_val += year.length;
                if (year.length == 2) {
                    if (year > 70) {
                        year = 1900 + (year - 0);
                    } else {
                        year = 2000 + (year - 0);
                    }
                }
            } else if (token == "MMM" || token == "NNN") {
                month = 0;
                for (var i = 0; i < MONTH_NAMES.length; i++) {
                    var month_name = MONTH_NAMES[i];
                    if (val.substring(i_val, i_val + month_name.length).toLowerCase() == month_name.toLowerCase()) {
                        if (token == "MMM" || (token == "NNN" && i > 11)) {
                            month = i + 1;
                            if (month > 12) {
                                month -= 12;
                            }
                            i_val += month_name.length;
                            break;
                        }
                    }
                }
                if ((month < 1) || (month > 12)) {
                    return 0;
                }
            } else if (token == "EE" || token == "E") {
                for (var i = 0; i < DAY_NAMES.length; i++) {
                    var day_name = DAY_NAMES[i];
                    if (val.substring(i_val, i_val + day_name.length).toLowerCase() == day_name.toLowerCase()) {
                        i_val += day_name.length;
                        break;
                    }
                }
            } else if (token == "MM" || token == "M") {
                month = _getInt(val, i_val, token.length, 2);
                if (month == null || (month < 1) || (month > 12)) {
                    return 0;
                }
                i_val += month.length;
            } else if (token == "dd" || token == "d") {
                date = _getInt(val, i_val, token.length, 2);
                if (date == null || (date < 1) || (date > 31)) {
                    return 0;
                }
                i_val += date.length;
            } else if (token == "hh" || token == "h") {
                hh = _getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 1) || (hh > 12)) {
                    return 0;
                }
                i_val += hh.length;
            } else if (token == "HH" || token == "H") {
                hh = _getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 0) || (hh > 23)) {
                    return 0;
                }
                i_val += hh.length;
            } else if (token == "KK" || token == "K") {
                hh = _getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 0) || (hh > 11)) {
                    return 0;
                }
                i_val += hh.length;
            } else if (token == "kk" || token == "k") {
                hh = _getInt(val, i_val, token.length, 2);
                if (hh == null || (hh < 1) || (hh > 24)) {
                    return 0;
                }
                i_val += hh.length;
                hh--;
            } else if (token == "mm" || token == "m") {
                mm = _getInt(val, i_val, token.length, 2);
                if (mm == null || (mm < 0) || (mm > 59)) {
                    return 0;
                }
                i_val += mm.length;
            } else if (token == "ss" || token == "s") {
                ss = _getInt(val, i_val, token.length, 2);
                if (ss == null || (ss < 0) || (ss > 59)) {
                    return 0;
                }
                i_val += ss.length;
            } else if (token == "a") {
                if (val.substring(i_val, i_val + 2).toLowerCase() == "am") {
                    ampm = "AM";
                } else if (val.substring(i_val, i_val + 2).toLowerCase() == "pm") {
                    ampm = "PM";
                } else {
                    return 0;
                }
                i_val += 2;
            } else {
                if (val.substring(i_val, i_val + token.length) != token) {
                    return 0;
                } else {
                    i_val += token.length;
                }
            }
        }
        // If there are any trailing characters left in the value, it doesn't match
        if (i_val != val.length) {
            return 0;
        }
        // Is date valid for month?
        if (month == 2) {
            // Check for leap year
            if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) { // leap year
                if (date > 29) {
                    return 0;
                }
            } else {
                if (date > 28) {
                    return 0;
                }
            }
        }
        if ((month == 4) || (month == 6) || (month == 9) || (month == 11)) {
            if (date > 30) {
                return 0;
            }
        }
        // Correct hours value
        if (hh < 12 && ampm == "PM") {
            hh = hh - 0 + 12;
        } else if (hh > 11 && ampm == "AM") {
            hh -= 12;
        }
        return new Date(year, month - 1, date, hh, mm, ss);
    }

    Date.prototype.formatDate = function (dateFmt) {
        return formatDate(this, dateFmt);
    };
    String.prototype.parseDate = function (dateFmt) {
        if (this.length < dateFmt.length) {
            dateFmt = dateFmt.slice(0, this.length);
        }
        return parseDate(this, dateFmt);
    };

    /**
     * replaceTmEval("{1+2}-{2-1}")
     */
    function replaceTmEval(data) {
        return data.replace(RegExp("({[A-Za-z0-9_+-]*})", "g"), function ($1) {
            return eval('(' + $1.replace(/[{}]+/g, "") + ')');
        });
    }

    /**
     * dateFmt:%y-%M-%d
     * %y-%M-{%d+1}
     * ex: new Date().formatDateTm('%y-%M-{%d-1}')
     *    new Date().formatDateTm('2012-1')
     */
    Date.prototype.formatDateTm = function (dateFmt) {
        var y = this.getFullYear();
        var m = this.getMonth() + 1;
        var d = this.getDate();

        var sDate = dateFmt.replaceAll("%y", y).replaceAll("%M", m).replaceAll("%d", d);
        sDate = replaceTmEval(sDate);

        var _y = 1900, _m = 0, _d = 1;
        var aDate = sDate.split('-');

        if (aDate.length > 0) _y = aDate[0];
        if (aDate.length > 1) _m = aDate[1] - 1;
        if (aDate.length > 2) _d = aDate[2];

        return new Date(_y, _m, _d).formatDate('yyyy-MM-dd');
    };

})();

